1. Field of the Invention
This invention relates to a resin composition for artificial marble. More particularly, it relates to a resin composition possessing excellent formability and permitting production of set articles of a marble-like appearance ideally usable as household utensils such as washstands and bathtubs and ornamental articles.
2. Description of the Prior Art
Heretofore, the practice of producing shaped articles having a marble-like appearance by mixing such radically polymerizable resins as unsaturated polyester resin and acrylic syrup with a varying filler, forming the resultant mixtures in a prescribed shape, and causing the shaped mixtures to set has been in vogue (U.S. Pat. No. 4,544,584, JP-A-50-107,045, and JP-A-52-129,722).
The compositions prepared by mixing radically polymerizable resins with a filler, however, have a disadvantage that since the shaped compositions lose volume during the course of setting, the articles to be formed of these compositions in any complicated shape unlike the simple shape of a plate are liable to sustain fractures and cracks and sacrifice the ease of mold release.
As a way of alleviating the shrinkage during the course of setting, the method which attains desired diminution of the shrinkage by preparing a resin composition comprising a radically polymerizable resin mixed in advance with a thermoplastic resin and causing the thermoplastic resin, during the course of setting, to induce phase separation or effervescence as a phenomenon to make up for loss of volume (U.S. Pat. No. 3,701,748) has been already known to the art. The polymerizable resin which is rendered less shrinkable by this method, however, has a disadvantage that the shaped article produced by setting the formed resin composition is opacified in whity shade and compelled to sacrifice the marble-like appearance endowed with transparency and suffer from loss of resistance to smearing.
An object of the present invention, therefore, is to provide a setting resin composition which permits production of shaped articles having a marble-like appearance endowed with transparency and exhibits high formability enough to prevent the articles formed in any complicated three-dimensional shape from sustaining fractures and cracks during the course of setting.
Another object of this invention to provide artificial marbles beautiful and rich in sensation of transparency enough to be used for production of such three-dimentional structures as washbowls and bathtubs and a method for the production of the artificial marble.